Provisional deadline structure of the dam body

摘要

PROBLEM TO BE SOLVED: To provide an inexpensive cofferdam structure with proper workability by reducing a dead space of an inner space.;SOLUTION: A cofferdam structure 100 for use in construction of a through-hole in an existing dam body 1 includes a cylindrical body 20, one opening 21 of which abuts on an upstream surface 3 of the dam body so as to surround a position 4a where the through-hole 2 is to be opened, and a semielliptic dome body 10 which closes the other opening 22 of the cylindrical body 20 and the cross-section of which assumes a convex shape to the upstream side of the dam body.;COPYRIGHT: (C)2013,JPO&INPIT